Manufacture of alkylated benzene hydrocarbons



W. KAPLAN March 14, 1944..

MANUFACTURE OF ALKYLATED BENZENE HYDROCARBONS Filed March 29, 1939 2Sheets-Sheet 1 x llhxl KuZwuwE Nu munzmozou N8 5335 Z 02-04mm .5535 Q%INVENTOR WILL/AM KAPLAN ATTORNEY W. KAPLAN March 14, 1944.

MANUFACTURE OF ALKYLATED BENZENE HYDROCARBONS '2 Sheets-Sheet 2 File dMarch 29, 1959 .Aldll Patented Mar. 14, 1944 UNITED STATES PATENTOFFICE- MANUFACTURE OF ALKYLATED BENZENE HYDROCABBONS I William Kaplan,Malverne, N. 2., assignor to Cities Service Oil Company, New York, N.Y., a corporation of Pennsylvania Application ltiarch 29, 1939, SerialNo. 264,693

4 Claims.

phase, the cracking results in the formation of a gasoline, the percentformed being roughly proportional to the time of digestion during theearlier stages of vcracking. The gasoline will contain 50% or more ofolefins; 5% to of aromatics, depending on the digestion temperature andthe nature of the charging oil; and the balance will be comprised ofnaphthenes and parafllnes. The chemical composition of the gasoline willremain substantially constant during the earlier stages of the cracking,that is, there will be very little variation in the composition at say5% gasoline or at gasoline formoderate proportion of aromatics areformed, (say to 40% in the gasoline fraction), and allowing the reactioninvolving further aromatic formation to take place at a lowertemperaturein the presence of a catalyst under conditions which result ,in theformation of appreciably smaller quantities of fixed gas.

Therefore, the primary object of the present invention is to provide animproved process for the manufacture ,of aromatic hydrocarbons, and moreparticularly aromatic compounds containing side-chains, and at the sametime avoid the excessive loss usually encountered in known purelythermal processes of the type referred to.

A further object of the invention is to provide an improved process forthe manufacture of side chain cyclic and aromatic hydrocarbons mation ina single pass. However, if the digestion is continued long enough,exothermic reactions take place which result in an increase in theproportion of aromatics in the gasoline fraction, with a reduction inthe proportion of unsaturates and other constituents. This exothermicreaction can be stopped at any desired point so as to obtain a productof any desired aromatic content. However, the exothermic reactionproceeds with the production of excessive amounts of fixed gas, and thegreater the percentage of aromatics in the gasoline,-the greater is thegas loss. As an example of such a process, a hydrocarbon oil such asnaphtha,.kerosene, or gas oil, is heated and vaporized, and theresulting vapors subjected to a long time thermal conversion treatmentat temperatures of about 950 F. to 1050 F. at a pressure of from 200 to500 lbs. per square inch. The original charging stock is converted intoa gasoline product containing from 40% to about 90% of aromatichydrocarbons, depending upon the length of the reaction period, with agas loss of from 30% to 40% of the original charging stock.

The process of the present invention is more particularly an improvementon this prior process for manufacturing aromatic hydrocarbons. Thepresent invention contemplates stopping the high temperature exothermicreaction when a from mineral oils in order to provide such hydrocarbonsfor various purposes such as solvents, chemicals, and compounds, for useas blending agents to increase the anti-knock value of relatively poorgasolines.

Accordingly, the improved process of the present invention comprises thesteps of subjecting a hydrocarbon oil such as a gas oil, kerosene ornaphtha, to a thermal conversion operation preferably while flowing in aconfined stream of restricted cross section through a long heated pipecoil, heating the oil to a temperature of from about 980 to 1020 F. at apressure of approximately 250 lbs. per square inch,'maintaining thehydrocarbon oil at approximately said temperature or slightly higher,for a period of time sufflcient to convert the oil into a productcontaining a substantial proportion of condensable constituents boilingbelow about i00 F.. which contains approximately 35% of aromatichydrocarbons, and approximately 45% of oleflnic type hydrocarbons,thereafter subjecting the vaporous products from the heating operation,and particularly the vapors including constituents boiling belowapproximately 500 F., tothe action of an alkylation and/or cyclizationcatalyst while maintaining the hydrocarbon in vapor state, whereby theolefinic hydrocarbons con-- tained in the mixture are reacted with thearomatic hydrocarbons to form side chain alkylated cyclic and aromaticcompounds, and further aromatic formation from unsaturates takesphosphorus pentoxicie, aluminum chloride, barium chloride, boron halide,the lower oxidesor sulfides of chromium, cobalt, molybdenum,

uranium and tungsten, and a silica gel reaction product with phosphoricacid. The catalytic reaction, is preferably carried out at a temperatureof approximately 700 F. and at a pressure of approximately 50 to 200lbs. per square inch.

Other. features, objects and advantages of the 6 improved process of thepresent invention will be apparent to those skilled in the art from thefollowing more detailed description thereof, taken in connection withthe accompanying drawings in which:

Fig. 1 is a more or less conventional diagrammatic elevational view ofassembled apparatus elements particularly adapted for carrying out theimproved process.

Fig. 2 is a view similar to Fig. 1 showing a modification of apparatusfor carrying out a modified form of the improvedprocess of the present,invention.

Fig. 3 is an enlarged broken sectional view illustrating a form ofrotary valve structure shown in Fig. 2 of the drawings. 4 I

Referring to Fig. 1 of the drawings, the crude hydrocarbon to be'usedfor the manufacture of aromatic hydrocarbons in accordance with theprocess of the present invention, is introduced into the apparatus underpressure by means of a pump (not shown) through a line 2, and preferablypassed through a plurality of heating tube banks 4, 6, 8 and i mountedin a pipe still furnace 12 which may be of usual and well-known type andstructure. The oil stock in passing through the tube banks'4 and 6 ispreferably heated to a temperature from about 920 to 950 F. andthereafter heated in the tube banks 8 and I0 to a temperature of. from980 to about 1020 F. at which temperature the highly heated products aredischarged through a transfer line it into the lower portion of anenlarged vertical reaction chamber E6.

The tube banks 8 and ill, or tube bank", is preferably of sufficientlength to give a substantial period of reaction time for breaking up andconverting substantial proportions of the hydrocarbons into productsboiling below 450 F. The highly heated products discharged into thereaction chamber ii are subjected to a relatively long time soakingreaction which is preferably exo-- thermic in nature, so that thetemperature actually rises in the chamber to a point of from 1000 to1070 F. at the top of'the chamber where the vapors are dischargedthrough a line is. Some of the exothermic reaction may take place in thetube bank l0 andds continued in the chamber l6 which is preferablyheavily insulated. By the time the conversion products reach the top ofthe chamber it, they preferably contain approximate-' ly 35% of aromatichydrocarbons and 45% of olefinic hydrocarbons in the fraction boilingbelow temperatures of from 400 to 450 F. Such a fraction suitable forsubsequent catalytic conversion may contain from approximately 35% toapproximately 55% of oleflnic hydrocarbons and from approximately 30% toapproximately 45% of aromatic hydrocarbons.

As the highly heated hydrocarbons discharge through the line It, theirtemperature is preferably reduced instantaneously to a point within therange of approximately 600 to 800 F. by introducing into the dischargingvapors a fluid cooling medium from a valved line 20. The resultingmixture passes on through a valved line 22 into a vapor separator 24where any condensed or unvaporized materials are separated from thehydrocarbon vapors.

In carrying out the reaction in the chamber i8, 7

some free carbon of the nature of carbon black is usually formed in thereaction chamber. Where this occurs, it may be readily blown from thechamber through a valved line 28. During the operation the liquidcollected in the vapor separator 24 is preferably withdrawn through avalved line 20 into a flash still 20, where vaporization of readilyvaporizable constituents is effected by reduction in pressure. Theunvaporized material is discharged from the still 20 as fuel oil througha valved line 32 while the vapors are conducted through valved lines 34and 88, a condenser 38, and a line 40, into a receiver 42. Thecondensate collected in receiver 42 may be used as the cooling fluid forcooling the vapors discharging through line l8, by withdrawing thecondensate through the valved line 20 which is provided with a pumpmounted therein. Any gas separated out in receiver 42 may be releasedthrough a valved line, and any excess condensate may be dischargedthrough a valved line 48. Instead of vaporizing the liquid collected inthe separator 24, it may be passed directly through lines 28, 38, thecooler 38, and the line 40, into the receiver 42, and reused as thecooling medium by forcingdt again through .the lin 20, excess liquidbeing withdrawn through the valved line 46.

The vapors separated out in the separator 24,

- and including the gas produced in the conversion adapted to efiect thealkylation of the aromatic hydrocarbons contained in the mixture ofvapors, as well as dehydrogenation and cyclization of oleflns. 'Thearomatic hydrocarbons are alkylated bythe gaseous oleflnic hydrocarbonsas well as by some parafiinic hydrocarbons, due to the influence of thecatalyst, so that side chain aromatic compounds are produced. Thearomatic hydrocarbons in the vapors in the line 48 comprise benzenederivatives which may contain some side chains. The alkylation mayalkylate at one or more positions in the benzene ring, so that a varietyof side chain benzene and cyclic hydrocarbon derivatives are formed.

Dehydrogenation and cyclization of oleflnes containing six or morecarbon atoms also occurs and the hydrogen will normally be consumed asprise one of the catalytic materials referred to above, deposited forexample, on clay or some inert carrier material supported in the chamber50. The reaction is preferably carried out at relatively lowtemperatures, for example. of the order of from 600 to 800 F. andpreferably-while the" vapors introduced through the line 40 arecontinuously maintained in the vapor state. The catalyzed reactionproducts from chamber 50 are withdrawn through a line 52 in which theproducts may be cooled, if desired, by introducing a tion is' desired atthe bottom of fractionating tower 82. In any case the products conductedthrough the line 52 may be discharged directly into avapor separator 58for the separation of any bons of lower boiling point produced by theprocess. If desired, the separator 58 may be entirely omitted and thevapors from the chamber 50 passed directly into the tower 82.

In the tower 62 the vapors are subjected to rectifying conditions, sothat a rectified higher boiling product is obtained at the bottom of thetower and withdrawn through a valved line 84, and an overhead vaporfraction is obtained which is withdrawn through a valved line 86,subjected to mounted therein, and then conducted into a receiverm. Thevapor separator 56 may be omitted if the lower portion oi the tower 62is used to remove the heavier polymers, and the light colored reflux isremoved as a side stream through line 78. Any of the unreacted gasesproduced by the process pass with the vapors from the tower 62 and areeventually separated out in the receiver it. These gases, comprisedprimarily of saturated hydrocarbons, such as methane, ethane andpropane, are discharged through an automatic pressure valve controlledline 12. In carrying out the rectification in the tower 62, a suitablereflux ratio is maintained therein by returning condensate from thereceiver 10 through a line H by means of a pump mounted therein, so asto produce a distillate boiling preferably below 450 F. The overheadproduct produced by the rectification is withdrawn from the receiver 10through a valved line 16, and if desired. an intermediate product may beproduced on the 'tower and withdrawn from any desired level therein as aside stream, as for example, through a valved line 18.

The product removed through the line it is ordinarily passed to astabilizer (not shown) and may have a boiling range of from about'10.

F. to 350 F. or 400 F.. and that withdrawn through the line 8%, aboiling range of from 425 to about 550 F.

The improved process of the present invention may be carried out inslightly modified manne? by utilizing the apparatus shown in Figs. 2 and3 of the drawings, which apparatus includes certain elements which areidentical with those used in Fig. 1. In describing the process inconnection with Fig. 2, therefore, the apparatus elements which are thesame as those shown in Fig. 1 will be referred to by the same referenccharacters.

In accordance with the modification of the process shown in Fig. 2, theoil to be converted is subjected to substantially the same treatment inthe furnace i2 as that described in connection condensing conditions ina condenser 68.

of the reaction products boiling below approximately 450 F. The exacttemperature and pressure conditions necessary for securing'approximately this conversion for any particular stock are readilydeterminable by conducting an exp rimental operation on any givencracking furnace and reaction coil. and correlating the gravity of theproduct with its hydrocarbon analysis.

The highly heated reaction products resulting from the treatment in thecoil 80 are conducted through a line 82 into a line 22 in which thetemperature of the products is suddenly reduced to a point below cokedeposition in the line by introducing a. cooling fluid into the vaporstream from suiting liquid removed and treated in the same with Fig. 1,the oil being introduced through the pipe 2 and passed in series throughthe tube banks 6, 8. 8 and II]. In the modified process, however, theproducts discharged through the transfer line it at a temperature offrom 980 to 1020 F. and at a pressure of approximately 250 lbs. persquare inch, are conducted through a reaction coil 80 mounted in atemperature controlled chamber in which the temperature is controlled bysupplying suitable tempering hot gases, for example, from thefurnace i2.to maintain the temperature, or not permit it to rise aboveapproximately 1070" F. at the outlet. In the formation of aromatichydrocarbons in the tube bank I0 and reaction coil 80, sufllcient timeis permitted to secure approximately 45% of oleflnic and 35% of aromatichydrocarbons in the condensate'portion gianner as that described inconnection with The, vapors separated in the separator 26 of Fig. 2 andcomprising constituents boiling up to a temperature of about 750 F.,including any normally gaseous constituents formed by the conversionreactions carried out in the furnace i2 and coil 80, are conductedthrough a line 86 to a catalytic reaction zone comprising a coil 86. Afinely divided catalyst such as one of the catalysts referred to above,which may be deposited on a solid carrier and contained in a supply bin89, is permitted to flow through a valved line 90 in which is mounted arotary feed and measuring valve 92. This material is discharged at acontrolled rate into the stream of vapors passing through the line 88and carried through the reaction coil 86.

The rotary valve or may be of any suitable type commonly used forfeeding solids at a controlled rate. For example, this valve maycomprise a rotary plug 86 provided with a pocket 96 for receiving thecatalytic material from the bin 88 through the line 90. At everyrotation of the plug 94, the material deposited in the pocket 95, whilein the position shown in Fig. 3, is discharged through the lower portionof the line 90 into the vapors in the line 86. The valve is preferablyvapor-tight and provided with a valved vent line 98 so that any vaporpicked up by the pocket 96 from the lower portion of line 90 will bevented through the line 98 without disturbing the material flowing underatmospheric pressure through the upper portion of the line 90.- For moreuniform distribution of catalyst in the vapor stream, the plugpreferably contain'sa about'700 F. and held at this temperature in thetaining the suspended catalytic material are discharged from thereaction coil 80 through a line ill into s, cyclone separator III whichmay be oi any usual form, but adapted to withstand relatively highpressures, and in which the suspended solid catalytic material isseparated. The solid catalyst is removed from the cyclone separatorthrough a valved line ill in which is mounted a rotary valve I which maybe of submntially identical structure to that of the valve If.

The cyclone separator III is preferably heavily insulated so that nocondensation is permitted. The separated vapors are discharged from thiscyclone separator through a line 52 and thereafter handled in' the samemanner as that described in connection with Fig. l of the drawings. Thecatalytic material discharged through the line I may be reviviiied andreused by returning it to the bin or hopper II. In the form of operationdescribed in connection with Fig. 1, two or more catalyst chambers I.may be used alternately, so that theone cut of the system may beconnected to certain equipment for revivifying the catalyst, after whichthe chamber may be cut back into the system and reused. In carrying outthe improved process, the va pors and gases conducted from the separatorI normally contain. a major portion of hydrocarbons boiling belowapproximately 400 1'. which is removed as an overhead product from thetower 62 since the aromatic hydrocarbons boiling within this range,after alkylation'by the catalytic reaction, have the widest held ofutility. For example, the alkylated benzene derivatives containing oneor more side chains of from 1 to 4 carbon atoms, are particularlydesirable for use as blending agents for increasing the anti-knock valueof motor fuels. However, the vapor products discharged from theseparatorfl also include higher boiling hydrocarbons which will include aromaticand cyclic compounds of a more complex nature than the simple benzenederivatives, i. e. naphthalene and anthracene derivatives. Suchcompounds after being alblated, are valuable for use as intermediates inthe manufacture of dyes and for many other purposes.

The products produced in accordance with the improved process of thepresent invention by the catalytic reaction, are preferably fractionatedinto rather narrow fractions and in some cases by close fractionation,so that individual aromatic hydrocarbons may be recovered for particularpurposes. The fractionation operation may be controlled so that aproduct boiling within the range suitable for motor fuel, is withdrawnthrough the line 16. When the operation has been carried out so thatapproximately 45% of oleilnic and 35% of aromatic hydrocarbons iscontained in the condensable portion of the vapor stream boiling below400' F;, removed from the separator 24, the .product boiling belowapproximately 400 F. and removed through the line 18 will containapproximately 85% of aromatic hydrocarbons comprised primarily ofbenzene derivatives containing one or more side chains.

A specific example of a typical operation in which a light straight rungas oil is introduced into the apparatus through the line 2, andsubjectedto the improved process is as follows:

Light gas oil is heated in the furnace ii to a discharge temperature of985 F. These vapors are then conducted to an enlarged reaction chamberat 225 pounds pressure such as the chamber It, where an exothermicreaction of intermediate degree is permitted to take place, the vaporsbeing discharged from the chamber at a temperature of 1025' It, andinstantaneously cooled to Y 16 7 86 of from 87 F. to 405' E, contains83% or aromatic hydrocarbons as determined by the Egloff and Morrellmethod (Industrial 8: Engineering Chemistry, vol. 18 (1926) 9 8,88354-356).

The heavy material removed from the bottom of go the tower comprisesapproximately 10% of the original charging stock, while the productcollected overhead, as referred to above, comprises approximately 50% orthe original charging stock to the furnace.

The gas loss on the whole operation is about -20% as compared to from to40% gas loss previously encountered in the manufacture of productscontaining high percentages of arcmatic compounds.

30 From the foregoing description, it is apparent that variousmodifications and alterations may be made in the process withoutdeparting from the spirit and scope of the invention, as defined by theaccompanying claims. Having thus described the invention in itspreferred form, what is claimed as new is:

1. The process 01' manufacturing side chain cyclic and armatichydrocarbons from petroleum oil distillates of substantially parafliniccharacter, which comprises passing the petroleum distillate chargingstock through a heating zone in a confined stream of restrictedcross-section and therein heating the distillate to a temperature offrom 950 to 1020" r2, thereafter subjecting the heated distillate to anexothermic reaction at a high temperature for a substantial period oftim during which the distillate is converted into a reaction mixturecontaining a substantial proportion of condensable products boilingbelow 400' F., said proportion containing from approximately 35% toapproximately of oleflnic hydrocarbons and from approximately 30% toapproximately 55% of aromatic hydrocarbons, cooling the resultingmixture of conversion products to condense high 55 boiling componentsthereof, but insufliclently to condense the constituents boiling up toapproximately 500 F., separating the condensed materials'from theresulting vapors and gases and passing the latter directly into acatalytic reac- 00 tion zone in intimate contact with a solid alkyiatiOnand cyclization catalyst, maintaining a reaction' temperature upwards ofabout 600 F. in said catalytic reaction zone which is sufficient toconvert the vapors and gases into the desired (is cyclic and aromatichydrocarbons, and fractionating the resulting reaction products torecover the desired hydrocarbons therefrom.

2. In the process of manufacturing side chain cyclic and aromatichydrocarbons in which an 7 olefinic, cyclic and aromatic hydrocarbonstock is subjected to alkylation conditions in the presence of analkylation catalyst, the improvement which comprises preparing ahydrocarbon stock for alkylation by cracking a mineral oil distillate ata temperature of from 950 to 1020 I". under conversion conditionsadapted to produce a substantial proportion of condensable materialbolling below a temperature of from 400 to 450 F., said materialcontaining from approximately 35% to approximately 55% of olefinichydrocarbons and from approximately 30% to approximately 45% of cyclicand aromatic hydrocarbons, subjecting the highly heated products of thecracking operation to cooling sufiicient to condense constituentsboiling above about 500 F. and leave a vapor fraction including saidcondensable material and the normally gaseous hydrocarbons produced bythe cracking operation, separating said vapor fraction from saidcondensed constituents as said hydrocarbon stock, and passing said vaporfraction while hot directly into an alkylation zone in intimate contactwith a solid alkylation catalyst at a temperature of from 600 to 800 F.to produce said side chain cyclic and aromatic hydrocarbons.

3. In the process of manufacturing side chain aromatic hydrocarbons inwhich a stock comprised of olefinic and aromatic hydrocarbons issubjected to alkylation conditions in the presence of an alkylationcatalyst, the improvement which comprises preparing the hydrocarbonstock for alkylation by cracking a mineraloil distillate at atemperature of from 950 to 1020" F.'under conversion conditionsadaptedto, produce a substantial proportion of condensable materialboiling below a temperature of from 400 to 450 F., said materialcontaining at least 30% each of olefinic hydrocarbons and aromatichydrocarbons; subjecting the highly heated products of the crackingoperation to cooling sufilcient to condense constituents boiling aboveabout 500 F. and leave a vapor fraction including said condensablematerial and the normally gaseous hydrocarbons produced by the crackingoperation,

separating said vapor fraction from said condensed constituents as saidhydrocarbon stock, and passing said vapor fraction while hot directlyinto an alkylation zone in intimate contact with a solid alkylationcatalyst at a temperture of from 600 to 800 F. to produce said sidechain aromatic hydrocarbons.

4. In the process of manufacturing side chain cyclic hydrocarbons andaromatic hydrocarbons in which a stock comprised of olefinic andaromatic hydrocarbons is subjected to alkylation and aromatizationconditions in the presence of an alkylation and aromatization catalyst,the improvement which comprises preparing the hydrocarbon stock for theoperation by cracking a mineral oil distillate at a temperature of from950 to 1020 F. under conversion conditions including an aromatic-formingexothermic reaction, stopping the exothermic reaction when thecondensable material in the reaction product boiling below a temperatureof from 400 to 450 F. contains approximately but not more thanapproximately 35% of aromatic hydrocarbons, subjecting the heatedproducts of the cracking operation to cooling sufficient to condenseconstituents boiling above about 500 F. and leave a vapor fractionincluding said condensable material and the normally gaseoushydrocarbons produced by the cracking operation, separating said vaporfraction from said condensed constituents as said hydrocarbon stock, andpassing said vapor fraction while hot directly into a reaction zone inintimate contact with a solid alkylation and aromatization catalyst at atemperature upwards of about 600 F. to produce said side chain cyclichydrocarbons and aromatic hydrocarbons and to substantially increase thequantity of aromatic hydrocarbons over the quantity contained in saidstock.

WILLIAM KAPLAN.

